Reproducibility of Maximum Respiratory Pressure Assessment: A Systematic Review and Meta-analysis

Abstract

Accurate assessment of maximum respiratory pressure is vital when tracking disease progression and devising treatment strategies. Previous studies indicate a learning effect when undertaking maximum respiratory pressure measurements. The extent of this learning effect and methodologies undertaken to mitigate this learning effect have not been investigated systematically. What is the magnitude of improvements in maximum respiratory pressure in response to respiratory muscle warm-up protocols and repeated measures of maximum respiratory pressure in healthy individuals and clinical populations? A comprehensive search of electronic databases was undertaken during August 2021 for studies examining the intrarater reliability of maximum inspiratory or expiratory pressure, or both, studies developing a protocol or an intervention to obtain maximum values, and studies analyzing the reliability of repeated maneuvers in a single testing session in healthy individuals and clinical populations. Included articles were analyzed critically using two appraisal tools. Standardized mean differences with 95%CIs were calculated and corrected for the sample size as a measure of the magnitude of change in maximum respiratory pressure outcomes. Of the 1,969 articles retrieved, 32 were included in the meta-analysis. Eighteen studies included healthy individuals and 14 studies included individuals with chronic medical conditions. The overall effect of inspiratory muscle warm-up protocols was higher (effects size [ES], 0.40; 95%CI, 0.17-0.63) in comparison with single testing session studies (ES, 0.20; 95%CI, 0.05-0.35) and studies performing repeated testing sessions of maximum respiratory pressure (ES, 0.14; 95%CI, 0.07-022). Inspiratory muscles warm-up procedures induce higher increases in maximum inspiratory pressure in comparison with single and repeated testing sessions of maximum respiratory pressure in healthy individuals. Warm-up protocols are more effective to obtain the maximum performance of inspiratory muscles in one testing session in comparison with other methods. PROSPERO; No.: CRD42022304591; URL: https://www.crd.york.ac.uk/prospero/.